Luminaire



June 19, 192s.

W. .A. DOREY LUMINAIRE original FiledV March 2e, 1924 INI/Emmi;

MA.) JL; Arm/mfr `lune 19, 1928.

W. A. DOREY LUMINAIRE original Filed March 2e, 1924 2 Sheets-Sheet 2 INVENTOR SLJULM Qt., M

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ATTORNEYS Patented June 19, 1928.

UNITED STATES- PATENT OFFICE.

'WILLIAM A. nonEY, 0E NEWARK, omo, AssIeNon, BY MEsNE ASSIGNMENTS, ro HoLorHANE COMPANY, 1Nc.,oE NEW Yoax, N.Y., A conroaA'rIoN 0E NEW Yoan.

LUM'INAIRE.

y Application led March 26, '1924, Serial No. 701,970. Renewed J'uly 20, 1926.

The objecty of m invention 4is the construction of luminaires having transmitting envelopes made up of a glass structure provided with prismatic corrugations arranged 6 to give concentration of light in one direction and a moderate spread of light in directions at right angles thereto. This is accomplished by one or more envelopes providing one surface consisting of concentric refractf l ing prisms designed to give a moderate con centration of light andV a surface cooperating therewith consisting of substantially parallel corrugations adapted to produce in'- creased concentration of the light in planes l at right angles to the corrugations and to permit transmission of the beam' in planes parallel to the corrugations Without substantial change in direction.

,Fig 1 is a plan view of the outer glass` illustrating the type of corrugations used in my appliance.

Fig. 2 is a plan View of an inner glass, and

Fig. 3v is a horizontal cross section of the combination of glases shown in Figs. 1 and 2.

Fig. 4 is a horizontal cross section of the glasses combined. v

The most importantuse ofthe invention is in cases Where it is desired to illuminate restricted areas from sources mounted at -the side and relatively close to the general surface of the area and at the same time it is desirable to cut olf the light at high angles; this sort of condition is illustrated by the condition of lighting. stair treads by luminaires recested or mounted `direct on the side Wall, in local lightingas in some varieties of machine tool Work and in other similar problems. In a great many other cases the reduction in the depth of the luminaire has great structural and operative advantages and makes the use of my invention much more satisfactory for the purpose than the ordinary' forms of projection devices employing parabolic mirrored reflectors.

In the figures the construction is shown 4as made up in plates of circular contour havin general surfaces which are portions of sp eresf The inner glass 23has its convex and the outer glass 24 has its inner concave surface covered with horizontal prisms 2,5 In Figs. 3 and 4, 26 is the light source considered as a point, the smooth inner surface 27 of the glass 23 being of such curvature tion.

surfacel covered With concentric prisms22,v

that the outer elements'of the cone of light included by it will be incident at angles Which will not cause serious losses due to "surface reflection. The angle of incidence of all other rays in the'cone will necessarily be less than this. The prisms 22 on plate 23 are so constructed that the extreme outerv rays from the source vproceeding through the glass make an angle of incidence on the 'cooperate 'Wit-h horizontal' parallel prisms, 4the concentric prisms bemg formed so as to gather Widely divergent Alight rays from a source into a beam of moderate divergence and the horizontal prisms being adapted to concentrate this beam in vertical planes. The distribution yin lateral planes will tend to remain of the sameyrlivergence as the conc of light originating 4from the concentric.

prism construction. The invention is of especia-l value in making effective use of a very large angle of light from the source to produce a beam of very small angle in vertical plane and considerable divergence in the lateral plane. While flat plates `may he used to good effect I prefer in general to use convex spherical contours because a greater angle of light may be included Without undue loss from surface reflection.

' I have shown this design 4of glass in circular form in order to simplify the descrip= It may very readily be applied to square, rectangular or other straight-sided panel forms for incorporation in lantern f shapes by making the flanges of the outline desired and Wholly Within the circular outline-shown and virtually cutting away the superfluous portions of the glasses by means of. side walls substantially perpendicular to v the flanges. 'The modification above described is applicable to glasses having plane surfaces, where it is desired to simplify the arrangement in panel form for use in lanterns and maximum inclusion of the light from the source is not essential. Tlie plates described singly or in groups are adapted for use where a beam of light of rectangular l from the concentric prisms, have a common apex (28) and it is evident, however, that 'these cones may have separate apices if such design is found desirable in order to modify the distribution in the resultant beam. The invention can be applied to a single pie-ce of glass as well as in a double structure.

' I claim:

l. A luminaire comprising a light source, and a glass transmitting screen having one surface provided with concentric prisms formed to gather Widely divergent rays from the source into a beam of moderate divergence and the opposed surface provided with parallel corrugations adapted to (concentrate this beam of light in lanes at ri ht .ingles to the corrugations ang to permit ivergence7 in planes parallel to the corrugations.

2. A luminaire comprising a li ht source, and a lass transmitting screen iaving an outwar surface provided with concentric prisms formed to gather Widely divergent rays (from the'source into a beam of mederate divergence and an inward surface provided with parallel corrugations adapted to` concentrate this beam of light in planes at rightl angles to the corrugations and to permit divergencein planes parallel to the corrugations. Y l

3. A luminaire comprising a. light source, and a glass transmitting screen consisting of two covers, an inner cover provided with concentric prisms on its outward. surface formed to gather widely divergent rays from the source into a beam of moderate divergence and an outer cover having on its inward surface parallel corrugations adapted to concentrate vthis beam of light in planes at right angles to the corrugations and to permit divergence in planes parallel to the corrugations.

4. A luminaire comprising a light source, and a glass transmitting screen having one surface provided` with. a system of curvilinear prisms formed to deviate divergent rays from the source towards the inner sides of the curves and the onnnscd surface provided with( substantially parallel corrugations adapted to increase the deviation of the rays in planes at right angles tothe corrugations.

5. A luminaire comprising a light source, and a glass transmitting screen having one surface provided with concentric prisms formed to gather Widely divergent rays from the source into a beam of moderate divergence and the opposed surface provided with substantially parallel corrugations adapted to concentrate this beam of light in planes at right angles to the corrugations, the axis of the concentric prisms being set at an angle with reference to the axis of the parallel corrugations.

6. A luminaire comprising a light source and a glass transmitting screen havin one `surface provided with a plurality o systems of curvilinear prisms formed to gather widely divergent rays from the source into beams of moderate divergence, and the opposed surface provided with substantially parallel corru ations adapted to concentrate these beams o light in planes at ri ht angles to the corrugations, the axesof tie curved prism systems being set at wideangles with reference to the axis of the parallel corrugations.

Signed at Newark, in thecounty o Lick ving, and State of Ohio, this '24th day of March, 1924.

WILLIAM Al Donar. 

